Pancreatic Hormone III, also known as pancreatic polypeptide (PP) was discovered relatively recently and has been less studied than the other known pancreatic hormones. It is knwon to occur in species of most (probably all) vertebrates, including humans. Studies on the avian form (APP) have indicated that the molecule may possess a paired helical core with each end of the peptide chain exposed at the surface. A segment corresponding to one end has been synthesized and shown to inhibit response to the native hormone in gastric assays. Other segments of the molecule, corresponding to the suspected regions of biological and structural information, will be synthesized. These, with corresponding sequences from the bovine analog (BPP), will be assayed for the major activities of APP, including gastric stimulation and lipolysis inhibition. They will also be assessed by physical measurements (CD and NMR) for discrete structure.